Metallic circuit for operating signaling devices.



No. 804,182. PATENTED NOV. 7, 1905. A. K. ANDRIANC & H. HERBSTRITT.METALLIC CIRCUIT FOR OPERATING SIGNALING DEVICES.

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APPLICATION FILED MAR.6, 1905.

OMwA'Yi a) nnrrn a STATES PATENT orrron.

ALBERT KOCH ANDRIANO AND HERMANN HERBSTRITT, OF SAN FRAN- (JISCO,CALIFORNIA.

METALLIC CIRCUIT FOR OPERATING SIGNALING DEVICES.

Specification of Letters Patent.

Patented Nov. 7, 1905.

/ Application filed March 6, 1905- Serial N0. 248,729-

To all whom it may concern.

Be it known that we, ALBERT KocH ANDRI- ANO, a citizen or the UnitedStates of America, and HERMANN HERBSTRITT, a subject of the GermanEmperor, residing in the city and county of San Francisco and State ofCalifornia, have invented new and useful Improvements in MetallicCircuits for Operating Signaling Devices, of which the following is aspecification.

This invention relates to improvements made in electrical circuits andmeans for selecting and operating thereon electrically-actuated devices,such as an electrical bell or signal or other means for communicationbetween one station and another selected station over a metalliccircuit.

The invention is applicable more especially to telephone systems whereina plurality of stations are connected by separate metallic circuits eachcomposed of a direct conductor and a return-conductor, and each stationis provided with selecting devices or switches, by means of which ametallic circuit composed of one of the conductors for the direct andanother for the return side of the circuit can be formed between onestation and another.

The object of the invention is to prevent the main circuit-lines or anyportion of the lines or conductors that form the circuit between onestation and another from receiving current or being affected by thecurrent from the battery or other source of energy employed to operatethe circuit to such a degree or extent as to produce'an electricalcondition on other lines or conductors that may be utilized for adjacentcircuits, and thereby operate or disturb the operation of the electricaldevices on such adjacent circuits.

To such end and object chiefly the invention consists in theconstruction, arrangement, and combination of direct conductors,return-conductors, selecting devices, and circuit-closing means, and abattery or source of electrical energy normally disconnected from theconductors and connectible therein for use through the selectingdevices, as hereinafter described, and pointed out in the claims.

The accompanying drawing, to which reference is made in the followingdescription, illustrates one application of our invention to metalliccircuits connecting a plurality of stations, each having an electricalbell or signaling device and switches or means for forming and operatingat will a metallic circuit with any other station in the system. Thedrawing represents diagrammatically station No. 1 connected in circuitwith station No. 3 and in the act of communicating with that stationthrough the bell or signaling device.

In applying our invention to a system of this kind, in which everystation has its own line-selecting device, two lines or conductors thatare individual to the station have terminals at contact-points inswitching devices at every other station, and through the medium ofthese switching devices one of the lines or conductors is selected forthe direct conductor and another for the return-conductor of the stationwith which communication is desired. For example, the lines 1 2, used asdirect conductors, have line-terminals a in the direct-line switch A,and the lines 3 4, used as return-con ductors, have correspondingterminals t in the return-line switch B. By setting the movable membersa b of the two switches to the lines individual to the selected stationwith which communication is desired the two lines or conductors selectedwill constitute a metallic circuit of which the direct line of thecall-receiving station will form one side and the returnline of thatstation will form the other side. To these two lines or conductors whichare individual to the station a bell m or other electrically-actuateddevice is permanently. connected by a lead 5, tied to the main line orconductor on one side and by a connection 6 running to the otherconductor. The battery or other source of energy employed is notdirectly connected with or into either line or conductor of the circuit,but is situated in a normally open circuit having two conductors 7 8leading from opposite sides or poles and provided withterminals in acircuit-closing means at each station having a stationary stop 10,forming the terminal of the line 8, and a second movable contact-stop12, forming the terminal of the line 7. At these two stops thebattery-circuit stands normally open at every station; but at the timeof use when the current is required for operating the circuit connectionis made through these stops 10 12 by connecting the movable member of asindicated at 18.

one line-switch a into one stop and the corresponding member of theother line-switch 6 into the other stop. For this purpose the movablemember Z) of the line-switch B is connected into the movable stop 13 ofthe key 20 by a connection 16, and the additional movable stop 12,situated behind the movable stop 13 of the key, is arranged to makecontact at the time of closing the key with a third stop 15, that formsthe terminal of a connection 17, leading from the movable member of theother line-switch. The contactstop 12 is placed for convenience behindthe movable stop 13 of the key, so that the same movement of the keywill close and complete the connection between one line-conductor andthe side 8 of the battery-circuit and between the other line-conductorand the remaining side 7 of that circuit. .In this arrangement of thecircuit-closing means the stop 12 should be insulated from the stop 13,

The effect of this arrangement is to disconnect and separate the sourceof current'from all the conductors of the main circuits under allconditions, excepting at the instant that the circuit is closed at thekey.

At all other times, the lines being opened and disconnected from thebattery, the current is prevented from setting up or producing either byconduction or induction a disturbing effect on any of the lines that areemployed for main circuits.

- The operation of completing the circuit for calling one station fromanother is illustrated in the diagram, where the subscriber at stationNo. 1 has made connection with station No. 3 by setting his switches a,6' on the proper line-terminals. On pressing the key 20 one side of thebattery will be closed on the con- ,ductor 4 through the connection 8.,the stop 10, the movable stop 13, and the connection 16, running to thereturn-switch b, thence out over the line t and through the connection 6at station No. 3 to the bell, thence from which the connection 5continues the circuit to the direct conductor 1. Over that line leadingto the calling-station the circuit is completed through the switch a atthat station and the connection 17 to the fixed stop 15. As the movablestop 12 touches the stop 15 at the moment that the key is closed againstthe stop 10, the circuit will be completed over the conductors specifiedand through the battery, and the bell-signal or other device which isconnected in the circuit between the two line-conductors will beoperated.

It will be evident that by using coils of-sufficiently high resistancefor the electromagnets of the bells or other signaling devices therewill be no disturbance or improper action of the other electricaldevices on those adjacent circuits that may have for a member one or theother, but not both of the mainline conductors. By using coils ofsufficiently high resistance for the electromagnets of the bells orinterposing proper resistance in the connections between the bell orother device 9 ing upon the other devices with which a circuit might beset up at the same time in an indirect manner by passing through theconductors of several stations, one or the other of which may constitutethe direct or the return side of the circuit that happens to be directlyconnected with the battery by its switching devices.

What we claim as our invention, and desire to secure by Letters Patent,is I l. A system of conductors for operating electrical devices betweenstations comprising a pluralityot' wires arranged between the stations,means for selecting any one wire for use as a direct conductor of acircuit individual to a station and another wire for use as thereturn-conductor of that circuit, an electricallyoperated devicepermanently connected into the direct conductor and the return-conductorindividual to a station, a source of current normally disconnected fromthe wires or conductors and circuit-closing means for connecting theselected direct conductor of a circuit into one side of the source ofelectricity and the return-conductor of said circuit into the remainingside.

2. The combination of a series of direct conductors andreturn-conductors arranged to form metallic circuits between stations, adirect-line switch and a return-line switch at each station forconnecting the station by a metallic circuit with anotherselectedstation and an electrically-operated device at each stationpermanently connected into the direct line and the retu rn-lineindividual to the station, a source of current normally'disconnectedfrom all the direct lines and return-lines, and circuit-closing meansfor connecting at will one side of the said source of'current into theselected direct line and the remaining side into the selectedreturn-line of a circuit.

3. The combination of a series of direct conductors andreturn-conductors arranged to form metallic circuits between stations, adirect-line switch and a return-line switch for completing a metalliccircuit between one station and another station by selecting the directline and the return-line individual to that station, anelectrically-operated device at each IIO In testimony whereof We havehereunto set our names to this specification in the presence IQ of twosubscribing witnesses.

ALBERT KOCH ANDRIANO. HERMANN HERBSTRITT. Witnesses:

EDWARD E. OSBORN. M. REGNER.

